From lindaw at snf.stanford.edu Wed May 2 13:18:19 2012
From: lindaw at snf.stanford.edu (lindaw at snf.stanford.edu)
Date: Wed, 2 May 2012 13:18:19 -0700
Subject: Problem drytek2 SNF 2012-05-02 13:18:19: can't tune O2 descum or poly at low power
Message-ID:
I tried to run O2 descum. Before I started I noticed that process 1 pressure setting was set for 500 mT. The power was at 0, as it should be. Set pressure back to 150mT, O2 flow 100 sccm, and the cap and coil at previous settings in log book. turned power up to ~60W forward, and could not get any reflected power drop off through the entire rotation of the cap. I tried running poly on process 2, that had worked fine yesterday. Before starting, i noticed that the power setting for poly was set at above 600W on the dial. I turned it back down to ~60W, and started the program. Pressure, gas flows normal, but situation same as for O2 on process 1. Could not get reflected power to drop off at all through the entire rotation of the Cap. Not even a tiny blip. Tried all the poly Coil and Cap setting in the log book, but nothing worked. No plasma. High reflected.
From eenriquez at snf.stanford.edu Wed May 2 14:15:11 2012
From: eenriquez at snf.stanford.edu (eenriquez at snf.stanford.edu)
Date: Wed, 2 May 2012 14:15:11 -0700
Subject: Problem drytek2 SNF 2012-05-02 13:18:19: can't tune O2 descum or poly at low power
Message-ID:
Retightened loose RF cable.
From gyama at snf.stanford.edu Wed May 2 14:25:44 2012
From: gyama at snf.stanford.edu (gyama at snf.stanford.edu)
Date: Wed, 2 May 2012 14:25:44 -0700
Subject: Problem drytek2 SNF 2012-05-02 14:25:43: RF power maxing out at ~90W
Message-ID:
REFL @ ~80W, tuning cap & coil not working for Pgm 1, O2 descum
From fpurkl at snf.stanford.edu Wed May 2 15:13:39 2012
From: fpurkl at snf.stanford.edu (fpurkl at snf.stanford.edu)
Date: Wed, 2 May 2012 15:13:39 -0700
Subject: Comment drytek2 SNF 2012-05-02 15:13:39: O2 descum seems to be working now
Message-ID:
O2 descum (receipe 1) seems to be working now. I got 500W forward with 2.5W reverse power.
From eenriquez at snf.stanford.edu Wed May 2 16:00:57 2012
From: eenriquez at snf.stanford.edu (eenriquez at snf.stanford.edu)
Date: Wed, 2 May 2012 16:00:57 -0700
Subject: Problem drytek2 SNF 2012-05-02 14:25:43: RF power maxing out at ~90W
Message-ID:
Unable to duplicate the problem. Ran O2 @ 500 W for 10 min (0 W reflected power).
From lindaw at snf.stanford.edu Mon May 14 11:07:10 2012
From: lindaw at snf.stanford.edu (lindaw at snf.stanford.edu)
Date: Mon, 14 May 2012 11:07:10 -0700
Subject: Comment drytek2 SNF 2012-05-14 11:07:09: Plasma quits during etch
Message-ID:
tuning for both O2 descum and Poly were a tad touchy. got both tuned nicely, then the plasma would just drop out for no apparent reason during etch. Maybe there is a loose RF wire/connection again???? It didn't happen every time the etch was run so it was somewhat sporadic.
Also, when the O2 descum was running well, the reflected power would sometimes drift quite a lot over the course of a 2 min etch. This was also somewhat sporadic.